Arrhythmias & electrophysiology
Significance of Different Electrogram Morphologies at the Onset of Ventricular Tachycardia Episodes
- retrospective study
Authors' conclusion
VT with an initiation morphology distinct from the subsequent VT is associated with a greater number of inducible VT morphologies, despite a comparable gross scar extent.
Study context
- Population
- Patients with structural heart disease who underwent catheter ablation for monomorphic ventricular tachycardia (VT) and had analyzable spontaneous VT episodes recorded by an implantable cardioverter defibrillatorpatients, 257 spontaneous VT episodes · type A only 58 · type B only 47 · both types 8
- Participants
- 113 patients
- Exposure
- Different-morphology initiation (type B) vs matching-morphology initiation (type A) of spontaneous VT
- type An = 58 (type A only)
- type Bn = 47 (type B only)
- both typesn = 8
Main finding
As reported in the abstract
Spontaneous VT episodes by initiation type
type A
147
events
type B
110
events
Observational data: associations, not effects.
Further findings
Number of inducible VT morphologies during ablation
| Comparison | incidence rate ratio (95% CI) | P value | |
|---|---|---|---|
| type-B-only group · after multivariable adjustment | 1.47 (1.15–1.87) | P = 0.002 | |
| 0.512Incidence rate ratio (log scale) |
| Outcome | Estimate | P value |
|---|---|---|
| Number of inducible VT morphologies during ablation — type-B-only group · more inducible VT morphologies in the type-B-only group | P = 0.012 |
Pre-VT R-R intervals and ventricular-paced baseline rhythm
- Type B initiation was associated with longer pre-VT R-R intervals and a more frequent ventricular-paced baseline rhythm
Scar extent
- Similar scar extent
- P = 0.184
Acute procedural outcomes, complications, VT recurrence, and composite outcomes
- Not significantly different between the groups
Original publication
Significance of Different Electrogram Morphologies at the Onset of Ventricular Tachycardia Episodes. Heart Rhythm. Published 4 September 2026. doi:10.1016/j.hrthm.2026.08.055
Summarised from the published abstract; every number is checked against it